UPMSP Weaving Technology study materials
UPMSP Weaving Technology study resources

UPMSP Weaving Technology: Fabric Defects

UPMSP Weaving Technology · Work through your exam, one topic at a time.

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Fabric Defects

This domain tests defect identification, root causes, mending decisions and the 4-point inspection system used to grade greige and finished fabric.

Core rules

  • Warp-way defects include missing end, tight end, loose end, warp float and end-out. Causes include warp breaks, dropper failure and sizing faults.
  • Weft-way defects include missing pick, double pick, weft crack, weft float and slub. Causes include weft stop failure, picking faults and poor yarn clearing.
  • Both-way and surface defects include holes, oil stains, reed marks, temple marks, selvedge defects and crease marks.
  • The 4-point system assigns points by defect length: up to 3 in = 1; over 3 to 6 in = 2; over 6 to 9 in = 3; over 9 in = 4. Holes up to 1 in = 2; over 1 in = 4.
  • Points are normally expressed per 100 square yards or per 100 linear yards, so the basis must be stated.
  • Mending is economic only when the defect can be repaired without weakening the cloth or changing appearance.

Worked example

A 100-yard roll, 60 in wide, has a 10-in warp float (4 points), a 2-in oil stain (1), a 0.5-in hole (2) and a 5-in weft crack (2). Total = 9 points. Area = 100 × 60 / 36 = 166.67 square yards. Points per 100 square yards = 9 × 100 / 166.67 = 5.4.

Traps

  • Scoring a hole by the same length scale as a surface defect.
  • Mixing points per 100 linear yards with points per 100 square yards.
  • Counting the same defect twice after mending.
  • Treating all stains as removable.
  • Recording a defect without its location and size.